An Irish way of saying "idiot" that is supposed to be inoffensive. "Idiot" could be viewed as calling someone literally dumb or a legitimate criticism, but "eejit" tends to imply that they aren't actually dumb but you just want to tease or banter with them, possibly over something silly or foolish they do or possibly just because you disagree and want to disagree in a fun way.
Scottish slang for idiot. often used to describe somebody who's just done something so incredibly stupid, that they should be considered mentally retarded.
person 1:"You see him o'er there?"
person 2:"yeah"
person 1: "he's a feckin' eejit"